Target Rifle Scopes – How They Work

Target rifle scopes come in all types of different shapes and sizes, but all work under the same basic principals when you strip down all of the built-in extras. How you use your scope will greatly depend on what you’re using it for in the first place.

If you’re a hunter, you may use your scope one way, and if you’re a long-distance target shooter, you’ll likely use it a bit differently. Regardless of what you’re using them for, it’s good to know what each individual working part of the scope is, and what it does.

This post will walk you through from the lens in the eyepiece, all the way to the other end.

The Tale of Two Lenses

Using the same principals as a common telescope, there are two lenses that are at work in every rifle scope; the ocular lens and the objective lens. There are other lenses that reside within the scope, but these vary in number depending on the quality, purposes, and brand of the design. For that reason, we’ll just go over what we can see and observe from the outside of the scope.

Ocular Lens

The ocular lens is the lens closest to your eye when looking into the scope. This lens magnifies the focal point of what the scope has honed in on. On a typical scope, this lens will be the smaller of the two major lenses.

Objective Lens

The objective lens is the larger of the two in most scopes. It’s larger because its job is to take in light and information, that is focused to a point within the scope. From that point of focus, the ocular lens magnifies the information, creating an amplified image of what the objective lens took in.

The Eyepiece

The eyepiece is the housing designed to accommodate the ocular lens. Most scope manufacturers recommend that the scope is situated on your rifle so that the eyepiece is around 3.5” to 4” away from your eye. This is to prevent causing damage to your eye due to recoil.

There are products available out there that attach to the eyepiece, that act as a padding to protect one from getting hit with the full force of the recoil. Most of these items are a rubber fitting that fits snugly to the eyepiece and provides eye protection, while preventing you from getting too close to the eyepiece.

Target Rifle Scopes

Beyond the Eyepiece

Here is where the waters might get muddy for some. Cheaper scopes will not have many of the adjustments that will come with the more expensive scopes. Aside from the Scope Tube and the Objective Bell (which are standard to all scopes), the following features are not equipped on every scope that’s out there.

Power Ring

This is a feature that comes with most scopes, but not all. This is the primary zoom and focus adjustment for the scope. Different scopes zoom in to different magnifications, much like different cameras have different zoom-in specs. Rotating the power ring will increase or decrease the level of the scope’s magnification.

Scope Tube

This is the stretch of tube between the eyepiece and the objective lens bell, that winds up being attached to the weapon via scope rings. Scope tube diameters have been standardized in order to have standard sizes of mounting ring sets.

The two most typical and standard sizes are the 1” outside diameter of the tube, and a 30mm outside diameter.

Long Distance Adjustments

The further out you go, the more of a factor the wind and bullet drop becomes. For the long-range target rifle scopes, super-precise targeting requirements, windage and elevation turrets are used to compensate for these issues.

Windage Turret

As the name of this turret suggests, this knob located on the right side of the scope anticipates for wind, when sighting in for the long-distance shot. By twisting it to the left or right, it slightly adjusts the horizontal settings. For most, it takes some trial and error to get the adjustments just right, often requiring a couple of test shots.

Elevation Turret

The elevation turret compensates for the gradual drop of the bullet that occurs over long distances. Usually used in conjunction with the windage turret, this also may require a couple of long-range test shots to hone it in. This turret is typically located to the left of the windage turret.

Parallax Error Adjustment Turret

To the left of the Elevation Turret (or opposite the windage turret), is the parallax turret. This turret is a fine tune adjustment that removes the positioning of your eye from causing a parallax effect, when a target is being viewed over a long distance.

A parallax error is when the location of your eye makes the target appear to be differently centered than it truly is.

Objective Bell

The objective bell is the housing that contains the objective lens. A larger objective bell will accommodate a larger lens and will make for more ambient light to reach into the ocular lens.

Target Rifle Scopes Extras

Just like anything else, scopes have been ushered into the 21st century. This means that you can get your hands on a scope bearing all kinds of features that make the scope more diverse, easier to use, smarter, and of course, more expensive.

  • Water Proofing/Fog Proofing through Gas Purging
  • Digital High Def Optics
  • Thermal Optics
  • Night Vision Optics
  • Bluetooth/Wi-Fi Connections
  • Video Recorders
  • Smart Automatic Range Adjustments
  • Ballistics Calculation Features
  • Smart Mil-Dot Reticles
  • Auxiliary Ballistics Lasers
  • Buttstock Battery Packs


You can get target rifle scopes with some of the above, or all of the above. However, if you like the sounds of the above, be prepared to pay anywhere between $600-$2,000, depending on the options and brand. Most of these options aren’t necessary but are fun.

Though having a scope dial itself in automatically sounds like a quick and easy option for the novice, there’s nothing wrong with learning how to do it yourself the old-fashioned way first, then bumping up to the fun stuff down the road.

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